Apparatus for making a plastic part



Jun 30, 1964 D.' A. HAMILTON APPARATUS FOR MAKING A PLASTIC PART Original Filed June 6, 1955 2 Sheets-Sheet 1 EERRFMIIM INVENTOR.

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June 30, 1964 2 Sheets-Sheet 2 INVENTOR. 00/Y/1L0 6? HAM/L 70/) D. A. HAMILTON APPARATUS FOR MAKING A PLASTIC PART Original Filed June 6; 1955 United States Patent APPARATUS FOR MAKING A PLASTIC PART Donald A. Hamilton, Burbank, Calih, assignor to Don Baxter, Inc, Glendale, Calif., a corporation of Nevada Original application June 6, 1955, Ser. No. 513,277, now

Patent No. 3,025,855, dated March 20, 1962. Divided and this application Aug. 21, 1961, Ser. No. 132,638

7 Claims. (CI. 18-42) My invention relates to a mold for making a connector which is particularly useful in the administration of intravenous solutions.

This application is a division of the inventors copending application Serial Number 513,277, filed June 6, 1955, now Patent No. 3,025,855.

In giving a blood transfusion, it is common practice to start with a suitable sterile solution, such as normal saline or a dextrose solution, in order to be sure the needle is properly situated in a patients vein and the procedure is going smoothly. After such smooth flow is established, blood is allowed to run in. Finally, the solution is again run to wash the blood out of the tubing into the patients vein. This practice creates a need for an administration assembly which permits either blood or solution at will to flow through the same needle. For this purpose a variety of assemblies have been used, ordinarily referred to as Y administration sets. In such administration sets, one leg of the Y is connected to a solution bottle, another leg is connected to the blood bottle, and the third leg is connected to the tube leading to the needle.

In recent years there has been a trend toward the use of a disposable administration set, that is, sets which are intended, after use of one administration, to be discarded. This imposes the necessity for having the administration sets and units of which they are composed of the lowest possible cost and the Y assemblies previously employed have been too costly.

My invention consists of an apparatus for making a Y connector which can administer two to four solutions to a patient at the same time with the use of only one injection needle. To accomplish this, the solutions enter into the connector made by my apparatus and there joined, pass into a common conduit to the needle and into the patient.

Previous to my invention, the Y devices available all had important disadvantages. Glass Y tubes were easily broken. Dipped plastic Y tubes were expensive and made awkward assemblies. Molded Y stoppers had to be made of rubber or other resilient material so as to remove the Y-shaped molding core. Such stoppers were difiicult to attach to the plastic drip housings. In emergencies, pressure was sometimes applied to administration sets to increase the rate of a transfusion and the results could be disastrous if the stopper were not permanently attached to the housing. None of these devices could be used to conveniently connect one passageway to three or four other passageways.

It is, therefore, an object of my invention to provide an apparatus for making a device which has at least two inlets and a single outlet.

A further object of the invention is to provide an apparatus for making a cap for an administration set housing which has two inlets and a single outlet suitable for use as a drip indicator.

The particular device is preferably formed of any of the well-known plastics, rubber or even metal. Such a device has heretofore been impractical to make because in the molding or casting process, it was found very ditiicult to form the cores for the mold. The reason for this is that ordinarily one pin was inserted in the mold which made the outlet and against this pin, two pins were positioned.

3,138,827. Patented June 30, 1964 These pins could be drawn out after the molding or casting of the connector but fins or flashings were left where the three pins connected to each other, thus obstructing the free flow of liquid through the connector. Being inside the part, this flash was difiicult to detect and more difficult to remove.

My invention comprises an apparatus for molding such a connector by the use of a novel type of pins in the mold which prevents the formation of fins or flashings on the interior and makes a smooth clean passage therethrough.

Other objects and advantages of my invention will be apparent from the following description of the preferred embodiments thereof:

In the drawings:

FIGURE 1 is an elevation of a connector made in accordance with my invention.

FIGURE 2 is a sectional view of said connector.

FIGURE 3 is a section taken on line 33 on FIG- URE 2.

FIGURE 4 is a sectional view showing the positions of the aforesaid pins during the molding process.

FIGURE 5 is a partial sectional view of a modification.

FIGURE 6 is a section taken on line 6-6 on FIG- URE 4.

FIGURE 7 is a sectional view of a modification.

FIGURE 8 is atop perspective view of the device shown in FIGURE 7.

FIGURE 9 is a bottom perspective view of the device shown in FIGURE 7.

FIGURE 10 is a sectional view of a modification.

FIGURE 11 is a sectional view-of the mold used in constructing the connector shown in FIGURE 7.

FIGURE 12 is a section taken on line 12-12 on FIG- URE 7.

A connector constructed in accordance with my invention comprises the cap 1 with extending bosses 2 and 3 on the upper side thereof and a downwardly extending boss 4. The bosses 2 and 3 have passages 5 and 6 therethrough and the boss 4 has a passage 7 passing therethrough. The passages 5 and 6 are connected with the passage 7 as shown at 8 and 9, respectively. It should be noted that the juncture between the passages 5 and 7 or 6 and 7 are on a long taper; i.e., the juncture 8 and 9, if extended, would meet the longitudinal axis of the passage 7, at a small angle, thus providing a large meeting area. The cone-shaped extension 13 helps provide smooth laminar flow from passages -5 and 6 into passage 7 and also eliminates any air pocket which might interfere with smooth flow through the passage 7. The bosses 2 and 3 are of such a size as to permit a rubber or plastic tube 10 to be forced thereon to form an air-tight seal and these tubings then are connected at their other ends to bottles of intravenous solutions or blood. If desired, the connector may be made of a plastic material similar to the plastic tube 10 and the two may be easily cemented together.

A housing 11 is forced into the annular groove 12. The housing 11 which may contain a filter, is connected to aplastic tube (not shown) leading to a needle which is inserted into the patient. If a clear housing is used, the drip rate of the solution can be seen as it passes out of the boss 4, thus providing a drip meter.

The form of the connector shown in FIGURE 5 is made by my novel apparatus and is suitable for use in laboratories for dividing the flow of air, gas, water, etc., from one main line into two or more supply lines. In this modification, the skirts for attaching the caps to a housing are unnecessary and the device consists of a body with the passages 5 and 6 meeting the passage 7 as shown at 8 and 9.

In the forms of my invention shown in FIGURES 7, 8, 9 and 10, the housing 21 has enlarged bores 22 and 23 which connect with the passages 24 and 25 and the dispensing passage 26. Again, the junctions of the passages 24 and 25 with the passage 26 are on a long gradual taper. In this type of construction, the tubes from the solution containers or blood containers are forced into the enlarged bores 22 and 23. The shoulder 47 prevents inserting the tubing so far as to occlude the opening 37a. Housing 39 is forced into groove 40 between the inner skirt 45 and the outer skirt 46 and connected to a plastic tube (not shown) leading to the administration needle. Groove 41 facilitates molding by making the wall thickness of the inner skirt 45 uniform, thus allowing cooling. Groove 41 also provides additional area to facilitate removing the part from the upper half 42 of the mold.

FIGURE 10, like FIGURE 5, shows a modification of the connector suitable for use in laboratories for dividing the flow of air, gas, water or other fluids from one main line into two or more supply lines.

The process of construction of my connector is illustrated in FIGURES 4 and 11. A mold 30 consists of an upper half 42 and a lower half 31. The upper half 42 is provided with openings 32 and 33 into which are fastened the cavity pins 34 and 35. The cavity pins have tapered lower extremities 36 which are ground out as shown in FIGURE 6 so as to fit snugly around the conical surface 37 of the core pin 38. The lower half 31 of the mold is provided with a stripper bushing 44, a core body 43 and a core pin 38. The core pin 38 is attached to the core body 43 and is free to rotate. Core pin 38 is also adjustable lengthwise so as to compensate for Wear and is spring-loaded at 49 so as to always engage cavity pins 34 and with the same tension.

As can be seen, the pins 34 and 35 thus make a sliding fit with the conical surface 37 of the pin 38. With this type of pin construction and juncture, no flash or fins are left to block the passage between the bores 24 and 25 and the outlet passage 26.

Any type of sprue hole can be used to permit the pouring of plastic into the cavity 31. After filling the cavity with plastic and allowing the same to set, the mold is opened, automatically disengaging the pins 34 and 35. The core body and the attached pin 38 are then pulled back in relation to the stripper bushing 44 and the finished connector is allowed to drop free.

I have found that the best results are obtained when the surface 37, if extended, would meet the longitudinal axis of the core pin at an angle of 1 to 20. If the angle is less than 1, flash or fins tend to form. If the angle is more than 20, the pin 38 wears excessively and must be adjusted more often. If the angle is greater than 20, the connecting area 8 and 9 of the passages is also decreased. The connecting area may be increased by using a larger passage 7, but in many cases the larger passage may be undesirable.

The connectors made by my apparatus can also be made with 3 or 4 passageways by providing additional cavity pins nesting onto the core pin 38.

I claim:

1. A mold having at least three core pins for forming a plastic part having a single passage which is divided into at least two passages comprising: a first mold section designed to form a portion of the outer surface of the part; a single pin extending axially into said mold section; a tip section on said single pin, said tip section slanting axially inwardly on at least two opposed sides; a second mold section adapted to form a further portion of the outer surface of the part; at least two pins extending from said second mold section towards the first mold section, the pins of at least one mold section being movable relative to said mold section and axially spring loaded to exert a force against the pins of the opposing mold section to prevent the formation of flash inside the plastic part; tip sections on each of said pins; and a beveled surface on each of said tip sections, each of said beveled surfaces being located on the side of the tip section closest to the center of the mold and being complementary to and adapted to seat against one of the slanted tip surfaces of the single pin.

2. A mold having at least three core pins for forming a plastic part comprising: two open ended mold sections adapted to meet in face to face relation; a single, centrally located pin projecting into one of said sections; a tip section on said pin, said tip section tapering axially inwardly on at least two opposed sides; at least two pins projecting into the other section of the mold, the distance between said pins being less than the diameter of the single pin; and tip sections on each of the two pins, the innermost surface of said tip sections tapering outwardly toward the single pin axis and being adapted to seat against one of the tapered sides of the single pin, whereby a portion of each of the two pins seats on a portion of the single pin to form an area of contact oblique to the respective pin axes, the pins of at least one mold section being movable relative to said mold section and axially spring loaded to exert a force against the engaged pins of the opposing mold section to prevent the formation of flash inside said plastic part.

3. A mold as set forth in claim 2 wherein the tip section of the single pin is conical in shape and the pin is free to rotate relative to the two pins of the other section.

4. A mold as set forth in claim 3 wherein the single pin is spring loaded and adjustable lengthwise, whereby a constant pressure of said pin against the two pins can be maintained despite wear of the pins.

5. A mold having at least three core pins for forming a plastic part in which a single passage is divided into at least two passages comprising: a lower mold section designed to form a portion of the outside of the part; a single pin having a conically tapered tip extending axially from said lower portion; an upper portion of said mold adapted to form a further portion of the outside of the part; at least two pins extending from said upper portion towards the lower portion of the mold, said pins being positioned so that a portion of each is in line with a portion of the single pin; generally conical tapered tip sections on each of said two pins; and an indentation on the axially inward surface of each of said tip sections, each of said indentations having the shape of a portion of a longitudinally sectioned cone and being adapted to slidably receive and engage a portion of the conically tapered tip of the single pin, the pins of at least one mold section movable relative to said mold section and axially spring loaded to exert a force against the engaged pins of the opposing mold section to prevent the formation of flash inside said plastic part.

6. A mold having at least three core pins for forming a plastic part in which a single passage is divided into at least two passages comprising: a lower mold section designed to form a portion of the outside of the part; a rotatable, floating single pin having a conically tapered tip extending axially from said lower portion; an upper portion of said mold adapted to form a further portion of the outside of the part; at least two pins extending from said upper portion towards the lower portion of the mold; generally conical tapered tip surfaces on each of said two pins; and an indentation on the axially inward side of each of said tip surfaces, said indentation having the shape of the smaller portion of a longitudinally sectioned cone and being adapted to receive and slidably engage a portion of the conically tapered tip surface of the single pin, said indentation and said portion of the single pin tip surface being oblique to the respective pin axes whereby the pins meet in partial end-to-end and partial sideto-side relation, the pins of at least one mold section movable relative to said mold section and axially spring loaded to exert a force against the engaged pins of the opposing mold section to prevent the formation of flash inside said plastic part.

7. A mold having at least three core pins for forming a plastic part in which a single passage is divided into at least two passages comprising: a lower mold section designed to form a portion of the outside of the part; a single pin having a conically tapered tip extending axially from said lower portion; an upper portion of said mold adapted to form a further portion of the outside of the part; at least two pins extending from said upper portion towards the lower portion of the mold; generally conical tapered tip sections on each of said two pins; indentation on the axially inward side of each of said two pins, said indentation defined by a generally conical female surface open on one side and being adapted to receive and slidably engage the conically tapered tip surface of the single pin, the pins of at least one mold section movable relative to said mold section and axially spring loaded to exert a force against the engaged pins of the opposing mold section to prevent the formation of flash inside said plastic part; and said lower section of the mold having a larger surface area than said upper portion and including a stripper bushing.

References Cited in the file of this patent UNITED STATES PATENTS Germany Nov. 5, 1931 

1. A MOLD HAVING AT LEAST THREE CORE PINS FOR FORMING A PLASTIC PART HAVING A SINGLE PASSAGE WHICH IS DIVIDED INTO AT LEAST TWO PASSAGES COMPRISING; A FIRST MOLD SECTION DESIGNED TO FORM A PORTION OF THE OUTER SURFACE OF THE PART; A SINGLE PIN EXTENDING AXIALLY INTO SAID MOLD SECTION; A TIP SECTION ON SAID SINGLE PIN, SAID TIP SECTION SLANTING AXIALLY INWARDLY ON AT LEAST TWO OPPOSED SIDES; A SECOND MOLD SECTION ADAPTED TO FORM A FURTHER PORTION OF THE OUTER SURFACE OF THE PART; AT LEAST TWO PINS EXTENDING FROM SAID SECOND MOLD SECTION TOWARDS THE FIRST MOLD SECTION, THE PINS OF AT LEAST ONE MOLD SECTION BEING MOV- 